Unless otherwise indicated herein, approaches described in this section are not prior art to the claims listed below and are not admitted to be prior art by inclusion in this section.
Virtual reality (VR) is an emerging feature in the consumer market. Typically a head-mounted display (HMD) is a key component of a VR system. In the context of VR, eye tracking (interchangeably referred to as “gaze tracking” herein) is a feature that offers a number of highly valued benefits. An example is that a user may stare at a virtual object to select it. That is, eye tracking allows for a natural mode of user interaction. By taking into account of gaze information, a processor, computing device or system can render graphics in a way to enhance the immersive experience of VR. Eye tracking also enables foveated rendering, which greatly reduces computational latency and energy.
However, there are a number of obstacles in providing eye tracking inside a tight space of a HMD. Specifically, in a given VR HMD, some dedicated cameras and likely some additional computational resources in the form of extra processors, memories, and circuit boards are required. Therefore, it is highly desirable to offer eye tracking at a minimal or even zero cost to the users.